do you think that senshi learned to harvest mandrakes the hard way? like do you think his first time pulling a mandrake out of the ground he heard the scream and needed time to recover but he tried it again later anyways with a different method?
if not... how did he know about cutting the mandrakes' heads?
I don't think so cause he most likely would have died from their scream being so close? Marcille was only "fine" because the giant bat was far from her with the screaming mandrake for most of it.
My best guess is that it was one of the things he learned from the orcs! He says "As well as how to interact with monsters" I imagine that includes catching them to eat or at least how to not die to them (Senshi had never died before he joined Laios' party)
Also I wonder how they continued to get the mandrakes after this one, cause they have their heads intact when they eat them again as candied mandrakes (I assume at least by what they look like. Edit: the ones senshi cuts in ch4 have their "lower jaw" cut off while marcille's had a full head, that's why I assume so) maybe they just really did just use a long rope? I don't remember if it gets mentioned.